Relay-controlling system



April 22, 1924. 1,491,344

. J. R. FRY

RELAY CONTROLLING SYTEM Filed Aug. 24, 1921 4 //1ve/720/": Jacob ffF/"y.

M/l/fy Patented Apr. 22, l

hi it? JACOB B. FRY, OF NEW YORK,

INCORPORATED,OF NEW YORK, N. "SE, A CORPORATION OF RELAY-CONTROLLING SYSTEM.

Application filed August 24, 1921. Serial No. 495,035.

T 0 all whom it may concern:

Be it known that 1,

Jason R. FRY, a citizen of the United States, residing at New York, in the county of Bronx, State of New York, Improvements have invented certain new and useful in Relay-Controlling Sysments, rangements for contro relays.

and more particularly to circuit arlling the operation of It is the object of this invention to provide a circuit arrangementsuch that a relay may be operated in response to the application of fluctuating or intermittent current of certain characteristics, to fluctuat ng or int other characteristics.

and will not respond ernnttent current of A feature ofthe invention is the use of induced currents for op erating a relay. The

coil by means of which currents are induced into the relay clrcuit is so designed that fluctuating current of certain char tics applled to the primary winding coil will cause the re acterisof said lay to operate, while fluctuating currents of other characteristics will not cause the actuation of the relay.

It is believed that an arrangement of this type has a wide field of utility, and the invention is therefore not to be limited by the specific disclosure,

which merely shows the invention adapted to meet the requirements of a field in which it is particularly useful.

The invention has been shown in connection with a cord circuit arranged for the use of an operator at a prlvate branch telephone exchange, in which arranged for through some of the stations are dialing. In a system of this type it is desirable that a signaling device he provided which may be controlled by a relay which current applied at a di 's responsive to ringing stant exchange in case the operator thereat desires to recall the private branch exchange operator.

systems of this nature In some difliculties have been encountered in insuring the correct operation of a relay of this type and the signal controlled by it, the private branch due to the fact that when exchange operator has established a through connection to an outoino trunk b means 2' a Y of which. a subscriber may dial to set up connections in the automatic exchange, 1t may occur that intermittent current fiow 7 cause d by theinterruptions of the line circuit due to 01": the subscrlbers dial, w

PATENT orria.

n. Y., assrenon To wnsrnnn ELECTRIC COMPANY,

new YORK.

the manipulation ill cause the enermay be operated tion of ringing current by distant station, but

in response to the applicaan operator at the will not be operated in response to any manipulation of a calling subscribers dial.

It is thought the invention will best be understood from the following detailed scription, reference being panying drawing.

dehad to the accom- In the drawing is shown a private branch exchange operators cord circuit together with a station in change, and an outgoing automatic switches at a the ,private branch extrunk leading to central oflice by means of which a connection may be extended to a called substationv The lower right-hand portion of the drawing shows art of an incoming trunk circuit, by means of which calls from outside oiiices may be extended to stations exchange.

in the private branch The operation of the system when a sub scriber in the sires a connection with another private branch exchange desubscriber,

whose station is in the same private branch exchange, will first be des cribed.

Assuming that substation 1 represents the station of the calling of the switchhoolr. at such illumination of lamp 4 subscriber. the removal station causes the due to the completion of a circuit from battery, lamp 4%, spring contact 3, the substation apparatus,

spring contact 2, to ground.

attracts the attention. of an the call by inserting 5 into the jack 6 of tion of lamp 4 operator, who answers the answering plug the calling station. The

The illuminainsertion of plug 5 into jack 6 opens the circuit of lamp 4,

and this lamp is extinguished.

is also completed from armature and A circuit battery, lamp 9,

back contact of relay 10, right armature and back contact of relay 11',

sleeve contacts of plug 5 and jack 6, to

ground. Calling supervisory lamp 9 is illuminated, but answering supervisory lamp 7 is not illuminated at this time since answering supervlsory relay 8 is operated.

The operating circuit traced from battery, the ture and back contact 0 for relay 8 may e outer left armaf relay 11, lower winding of induction coil 20, winding of relay 8, lower normal contact of key 29, ring contacts of plug 5 and jack 6, the line loop and the apparatus at substation 1, tip contacts of jack 6 and plug 5, upper normal contact of key 29, upper winding of induction coil 20, and inner left armature and contact of relay 11, to ground. The operator depresses listening key to connect her telephone head set across the tip and ring conductors of the line, and con verses with the calling subscriber. Upon learning that the call is for a station in the private branch exchange, she inserts plug 16 into another jack corres mnding to jack 6, but serving the called subscriber. and depresses ringing key 30 to signal the callefl subscribe-r in the usual manner.

In order to keep the description and disclosure as simple as possible. it will. be assumed that the stations in the private branch exchange are represented at the up erators position by one jack only which serves both as the calling and answering jack. l v hen the operator plugs into a jack 6, the control of lamp 4 removed from the subscriber to whom such jack assigned, regardless oi whether the operator plugs in to answer a call or to signal a wanted tion. The insertion of plug 5 causes spring contacts 2 and 3 to be opened to prevent further illumination of the lamp.

The operator intermittently actuates ring ing key 30 until. the called subscriber responds. The response of the called subscriber is indicated to the operator by the extinguislnnent of lamp 9 dr. to the energization of callin supervisory relay l0. Relay 10 is energized in a circuit from battery, outer left ari uati-ire and back contact of relay 11, lower winding of induction coil. 20, winding of relay 10. lower normal contact of relay 15. lower normal contact of k I 30, ring contacts of plug 16. the jack corresponding to jack 6, and through the loop of the called substation line. tip contacts cli ping 16 and associated jack, upper nor ma l contact of key 30, upper normal contact of relay l5 upper winding of induction coil 20, inner left armatin'e and back contact of relay 11, to ground.

Talking current is supplied to the called subscriber over the circuit above traced. Talking current is supplied to the calling subscriber from the same source through answering supervisory relay 8 and the tip and ring conductors of the cord circuit in an obvious manner. 7

.l hen conversation is completed and connection is no longer desired, the calling and called subscribers replace their receivers. thus causing the deeuergization of supervisory relays 8 and 10 respectively, and the illumination of supervisory lamps 7 and 9. Upon observing the lighting of lamps 7 and 9' the ground for causing sh.

operator removes plugs and 16 from the jacks with which they have been associated, thus restoring the control of the line signals to the respective subscriber.

The operation of the system in case a subscriber in the private branch exchange desires a connection to a subscriber in a distant mechanical oilicc will now be described.

The call is originated and answered and conversation takes place between the calling subscriber and the operator in the same manner as previously (lest; .d and lfilllp 9 is illuminated as previously described. The operator now proceeeds to test in the Well known manner trunk acks corresponding to jack 1? until an idle trunk is encountered whereupon plug 16 is fully inserted into the jack of such idle trunk. A circuit is then completed from battery, winding of relay l8, sleeve contacts of jack 1'? and plug 16, winding of relay 11, to ground.

Relay 11 is energized in this circuit and at its right armature opens the circuit of lamp 9 which is thereupon extinguished. The energization of relay 11 also completes a circuit from battery, outer left armature and front contact of relay 11, winding of relay l3, armature and front contact of relay 8, sleeve contacts of l and jack 6. to

encrgization of relay 13, which locks through its left armature to ground at a normal contact of theoperators listei'iing key 34 It should he observed that the energiz on or re ays l1 and 13 disconnects the source of battery supply from the primary windings of induction coil 20, and bridges these windings across the tip and ring conductors of the cord circuit with condenser 12 in series therewith. Relays 8 and 10 remain energized by means of current supplied over the trunk conductors and lamps T and 9 are ncintained extinguished.

The operator now proceeds to direct auto- "c switches. brushes of which are indicated genefiall E22 and 23 by means or a calling dial 21. of any well known i p0. As soon as the dial lea es its normal osh tion, contact 4-0 is closed and a circuit is completed from grounded battery. contact 40, winding of relay 15, to ground. Relay 1? is energized and extends ran the tip and ring trunk conductors through to the impulse spring contact 41 which is intermittently operated during the return movement of the dial. After the operator has dialed all of the digits of the wanted number, contact 40 is opened and relay 15 releases so that she is free to answer another call. The called station. indicated in this case at 24, is signaled in the well known manner by means of ringing apparatus associated with the automatic switches. The calling and called subscribers are supplied with talking current from one of the automatic switches in the well known manner and current flow through the tip and ring conductors and the connecting circuits maintains relay 8 ei'lergzed to prevent the illumination of lamp 7'. Lamp 9 is not illuminated at this time due to the fact that relay 11 is energized over this lead circuit.

When the conversation is completed, the subscribers replace their receivers and cause the release of the automatic switches in the well understood manner. The release of the automatic switches disconnects the source oi current supply from the trunk, thus allowing relays 8 and 10 to be released, causing in. turn the illumination of lamp 7 The operator upon observing the lighting of this lamp removes plugs 5 and 16 from jacks 6 and 17 respectively. Relay 11 is thereupon released and causes the. deenergization of relay 13 leaving the apparatus in its normal conditlon.

In case a call is to be extended from a distant ofiice to a station in the private branch exchange, the operation is as follows. The trunk associated with jack 25 shown in the lower right-hand portion of the drawing is seized at the distant point either by an operator or by an automatic switch. Closure of the trunk line loop causes the energization of relay 2'? and the resultant illumination of trunk signal lamp 28. The'private branch exchange operator upon observing the lighting of signal lamp 28, inserts plug 16 into trunk ack 25 whereupon a circuit is completed from battery, winding of cut-oil rela 26, sleeve contacts of jack 25 and plug 16. and the winding of relay 11, to ground. Relays 11 and 26 are energized in this circuit, relay 11 opening the circuit of lamp 9 and preventing its operation. while relay 26 causes the release of relay 2'? and the resultant extinguishment Oi lamp 253. lly depressing listening key the operator may converse with the distant operator or the subscriber initiating the call and learn the number of the line wanted in the private branchexchange. She thereupon inserts plug 5 into the jack 6 and signals the wanted station by means of ringing key 29 which. is actuated intermittently until the called subscriber answers, whereupon the energization of relay 8 causes lamp 7 to be extinguished. Lamp 7 was lighted as soon as plug 5 was inserted into jack 6. With relays 8 and 11 energized, the previously traced circuit for relay 13 is again completed and this relay is energized and locked previously described. Supervision is accomplished as previously described and the illumination of lamps 7 and 9 gives the operator the disconnect signals. The re moval of plugs 5 and 16 from their associated jacks causes the restoration of the apparatus in an obvious manner.

It should be noted that if the operator at the distant exchange wishes to recall the n-irate branch exchange operator for any reason, she may do so simply by applying ringing current across the tip and ring conductors of the interofhce trunk. Ringing current flows in this circuit from a source of ringing current as, upper contact oflrey 45, over the tip conductor of the trunk, tip contacts of jack and plug 16, upper normal contact of key 30, upper normal contact of relay 15, upper primary winding of coil 20, inner left armature and front contact of relay 11, condenser 12, lower primary winding of induction coil 20, winding of relay 10. lower normal. contacts of relay 15 and. key 80, ring contacts of plug 16 and jack 25, and the tip conductor of said trunk, back to the source of ringing current 4-4- by way of the lower contact of key 45. Induction coil 20 is so designed that the application of ringing current to its primary winding allows sutlicient current to be induced into its secondary winding to cause the energization of relay 19. The energization of relay 19 completes an obvious circuit for illuminatinglantip 9 to give the private branch exchange operator the recall signal. The primary windings of induction coil 20 are designed to be of relatively high impedance, but the choking efi ect of this impedance not sufficient to prevent passage of the substantially sinuous waves of ringingcurrent in suliicient strength to cause energizing cur rent for relay19 to flow in the secondary winding of the coil.

In systems of the type under eonsideration it is frequently desirable that a through dialing connection be established by means of the operators cord circuit from a station in a private branch exchange to a trunk leading to automatic switches. This be desirable 'l or several reasons. For instance, at night when the operator has left the board, it may be desirable to provide service to'certain ones of the stations. Again, it may happen that a subscriber wishes to set up a number of connections in a distant automatic exchange, in which case it would be undesirable to have the operator give him a new trunk each time.

In the case of a through dialing connection the operator answers the call as previously described and then hunts for an idle trunk leading to the automatic, exchange and inserts plug 16 into the jack 17 of such trunk. Relays 11 and 18 are operated as previously described as are also relays 8 and 10. The operator is then free to attend to other calls since the subscriber by manipulating his dial 42 may set up his own connections and release them at will as he has a full metallic two-conductor circuit from his substation to the switches which he can control in a manner well known in the art. The primary windings of induction coil 20 and condenser 12 in series therewith, are bridged. across the line, but the interruptions of the line circuit due to the operation of dial e2 do not caus relay 19 to be energized to give a false recall signal to the private branch exchange operator. This is due to the fact that the high impedance of the primary WlDCllD 2 the coil 20 has a strong choking effect due to the fact that the current fluctuations or changes are much sharper and occur different frequency than those of the current.

.lt further to be observed that the inclusion of relay 19, which controls the recall signal, in the secondary winding of an induction coil, the primary of which allows fluctuating current of certain characteristics to pass and prevents fluctuating currents of other characteristics to pass in appreciable quantities, accomplishes a result which is highly desirable. That is, a control Oi relay 19 is accomplished by means of which this relay may be positively actuated by ringing current and be just as positively prevented from operation due to fluctuations in the line during operation of the dial 42.

hat is claimed is:

1. In a telephone exchange system, incoming and outgoing lines, a link circuit including talking conductors for interconnecting said lines, a signal associated with said link circuit, a relay to control said signal, an induction coil including a primary and a secondary winding, a circuit including said relay and said secondary winding, a source of alternating current, means to apply said alternating current to the talking conductors of said link circuit, a source of potential, means to establish conn ction from said source of potential to the talking conductors of said link circuit through the primary winding of induction coil at one stage of operation, and means operative at another of operation to bridge said primary winding across said talking conductors to induce operating current for said relay in said secondary winding when said alternating current is applied to display said signal.

2. In a telephone exchange s stem, an incoming line, a plurality of variously characterized outgoing lines, a link circuit including talking conductors for extending said incoming line to a desired one of said outgoing lines, a signal associated with said link circuit, a relay to control said signal, an induction coil including a primary and a secondary winding, a circuit including said relay and said secondary winding, a source of potential, means operative when a connection is extended to an outgoing line of certain characteristics to supply current from said source to the talking conductors or said link circuit through the primary windings of said coil, and means operative when a connection is extended to an outline of other characteristics to bridge said primary windings of said induction coil across the talking conductors of said link circuit to render said relay responsive to the application of alternating current to the talking conductors of said link circuit.

3. In a telephone exchange system, an incomin line, a plurality of variously charcterized outgoing lines, a link circuit for extending said incoming line to a desired one of said outgoing lines, a signal associated with said link circuit, a relay to control said signal, an induction coil including a primary and a secondary winding, a circuit including said relay and said secondary "winding, and means to utilize said primary winding either as a battery feed coil or as the primary winding of a transformer t operate said relay, in accordance with the character of the outgoing line to which connection has been established.

4-. In a telephone exchange system, an incoming line. a plurality of outgoing lines, a link circuit for extending said incoming line to a desired one of said outgoing lines, means for applying currents of difierent characteristics to the conductors: of said link circuit, a associated with said link circuit, relay for operating said signal, an induction coil including a primary and a secondary winding, a circuit including said relay and said secondary winding, said induction coil being arranged to permit the operation of said relay only in response to the application of current of certain characteristics.

In witness whereof, I hereunto subscribe my name this 10th day 01": August A. D.,

JACOB R. FRY. 

